more faithful grammar

1 files changed, 36 insertions, 31 deletions

diff --git a/codegen.c b/codegen.c
index 955a095..a32046b 100644
--- a/codegen.c
+++ b/codegen.c
@@ -300,42 +300,20 @@ static void emit_var_ref(
 
 static void emit_stmt(FILE* outfile, const struct stmt_node* node);
 
-static struct var_def* emit_var_decl(
+static void emit_var_decl(
     FILE* outfile,
     const struct var_decl_node* node
 ) {
     struct lval_def var_dst =
         make_stack_lval(outfile, node->def_ref->resolved_type);
+    node->def_ref->loc = var_dst.loc;
 
     fprintf(outfile, "\t; '%s' lives in: ", node->def_ref->name);
     emit_storage_loc(outfile, &var_dst.loc, var_dst.type->sz);
     fprintf(outfile, "\n");
 
-    struct var_def* var_def = node->def_ref;
-    var_def->loc = var_dst.loc;
-    return var_def;
-}
-
-static struct lval_def emit_lval(
-    FILE* outfile,
-    const struct lval_node* node
-) {
-    struct var_def* var_def;
-    switch (node->type) {
-        case LVAL_VAR_DECL:
-            var_def = emit_var_decl(outfile, &node->inner.var_decl);
-            return (struct lval_def) {
-                .loc = var_def->loc,
-                .type = var_def->resolved_type,
-            };
-        case LVAL_VAR_REF:
-            var_def = node->inner.var_ref.def_ref;
-            return (struct lval_def) {
-                .loc = var_def->loc,
-                .type = var_def->resolved_type,
-            };
-    }
-    CGEN_PANIC("unknown lval type: %d", node->type);
+    if (node->initial_value != NULL)
+        emit_expr(outfile, node->initial_value, &var_dst);
 }
 
 static void emit_assignment(
@@ -343,7 +321,18 @@ static void emit_assignment(
     const struct assign_node* node,
     const struct lval_def* dst
 ) {
-    const struct lval_def lval_def = emit_lval(outfile, &node->lval);
+    struct lval_def lval_def;
+    switch (node->lval->type) {
+        case EXPR_VAR_REF:
+            struct var_ref_node* var_ref = &node->lval->inner.var_ref;
+            lval_def = (struct lval_def) {
+                .type = var_ref->def_ref->resolved_type,
+                .loc = var_ref->def_ref->loc,
+            };
+            break;
+        default:
+            CGEN_PANIC("expression is not assignable");
+    }
     emit_expr(outfile, node->rval, &lval_def);
     if (dst != NULL) emit_mov(outfile, dst, &lval_def.loc);
 }
@@ -356,8 +345,8 @@ static void emit_call(
     unsigned long long orig_bp_offset = scope->bp_offset;
     unsigned long long arg_bp_offset = orig_bp_offset;
  
-    struct args_decl_node* arg_decl = node->called_fn_ref->args;
-    struct args_eval_node* arg_eval = node->args;
+    struct decl_list_node* arg_decl = node->called_fn_ref->args;
+    struct expr_list_node* arg_eval = node->args;
     while (arg_decl != NULL && arg_eval != NULL) {
         struct lval_def arg_dst =
             make_stack_lval(outfile, arg_decl->decl->def_ref->resolved_type);
@@ -601,10 +590,26 @@ static void emit_if(FILE* outfile, const struct if_node* node) {
     exit_scope(node->scope, true);
 }
 
+static void emit_expr_list(FILE* outfile, const struct expr_list_node* node) {
+    for (; node != NULL; node = node->next)
+        emit_expr(outfile, node->expr, NULL);
+}
+
+static void emit_loop_init(FILE* outfile, const struct loop_init_node* node) {
+    switch (node->type) {
+        case INIT_EXPR_LIST:
+            emit_expr_list(outfile, node->expr_list);
+            break;
+        case INIT_DECL:
+            emit_var_decl(outfile, node->decl);
+            break;
+    }
+}
+
 static void emit_loop(FILE* outfile, const struct loop_node* node) {
     enter_scope(node->scope, scope->bp_offset);
 
-    if (node->init != NULL) emit_expr(outfile, node->init, NULL);
+    if (node->init != NULL) emit_loop_init(outfile, node->init);
 
     unsigned long long loop_num = ++loop_counter;
     if (node->cond != NULL) {
@@ -671,7 +676,7 @@ static void emit_fn_decl(FILE* outfile, const struct fn_decl_node* node) {
 
     long long spilled_bp_ofs = -16; // return address + old bp
     unsigned char arg_regnum = 0;
-    struct args_decl_node* arg_decl = node->args;
+    struct decl_list_node* arg_decl = node->args;
     for (; arg_decl != NULL; arg_decl = arg_decl->next) {
         struct var_def* arg_def = arg_decl->decl->def_ref;
         struct lval_def arg_dst =